"Right now… you can dim the entire screen or have a smaller display. We thought there should be something better," says Partha Ranganathan, a researcher at HP Labs.
You're on a long-distance flight with a two-hour DVD to watch but only 90 minutes of battery power left on your laptop. You're unexpectedly detained out of town without the charger for your mobile phone. Your MP3 player runs out of steam just when you locate that rare song to download.
We're more reliant than ever on our mobile devices, but battery life remains a problem. Improvements in battery capacity simply haven't kept pace with ever-more-powerful processors.